Article

“Solid state fermentation for the production of alkaline protease by Bacillus cereus 1173900 using proteinaceous tannery solid waste.

Current science (Impact Factor: 0.83). 01/2011; 100:726-730.

ABSTRACT Animal fleshing, the major proteinaceous solid waste
generated from leather industry, was used as substrate
for the production of alkaline protease by Bacillus
cereus 1173900 in solid-state fermentation (SSF).
Maximum protease activity of 12,310 U/g was observed
at 60 h in SSF crude extract. The extracted
protease enzyme was purified by 53.64-fold through
ammonium sulphate precipitation and chromatography
separation in Sephadex G-100. The purified protease
had a specific activity of 201.6 (U/mg). The molecular
weight of the purified enzyme was 66 kDa, determined
by SDS–PAGE. The zymogram also revealed a clear
hydrolytic zone due to proteolytic activity, which
coincided with the band obtained with SDS–PAGE.
Enzyme activity was inhibited by EDTA, suggesting
that the enzyme belongs to metalloprotease(s).

0 Bookmarks
 · 
218 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: We resolved a recent controversy on the structure of the Ce L(3) x-ray absorption spectra (XAS) of CeFe(2); i.e., which of the single impurity Anderson model (SIAM) and the first-principles band calculations based on the density-functional theory (DFT) describes more appropriately the Ce 4f states and their contribution to the Ce L(3) XAS? For this purpose, we examined the core-hole effect in Ce L(3) XAS as an application of our new method taking advantage of resonant x-ray emission spectroscopy. Our result clearly shows that the Ce L(3) XAS structure is caused by the mixed valence 4f character revealed by the core-hole potential effect as indicated by SIAM, but denies the possibility that the L(3) XAS structure is caused by the 5d band structure with a very small core-hole effect as predicted by band calculations based on DFT.
    Physical Review Letters 01/2012; 108(3):036403. · 7.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cow dung, a cheap and easily available source of energy, was used as the substrate for the production of alkaline protease by solid-state fermentation using the Bacillus subtilis strain VV. In order to achieve the maximum yield of this enzyme, the following optimum process parameters are needed: fermentation period (72 h), pH (10.0), moisture content (140%), inoculum (25%), temperature (30-40°C), carbon source (2% (w/w) maltose) and nitrogen source (1% (w/w) urea). The protease was stable over a broad temperature range (30-50°C) and pH (8.0-10.0), with maximum activity at 50°C and pH 10.0. Among the divalent ions tested, Ca(2+) (0.01 M) increased enzyme activity. The purified protease, after being subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was found to have a molecular mass of 38.5 kDa. The enzyme was solvent-and surfactant-stable and showed activity even after 24 h incubation along with various commercially available detergents. This enzyme possessed dehairing properties for animal hide after 16 h of incubation at room temperature. From these results it is evident that cow dung is a potential substrate for the production of a detergent-stable, dehairing protease by B. subtilis. This enzyme has a lot of potential applications in the detergent and leather-processing industries.
    SpringerPlus 01/2012; 1:76.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Agro-industrial residues and cow dung were used as the substrate for the production of alkaline protease by Bacillus cereus strain AT. The bacterial strain Bacillus cereus strain AT produced a high level of protease using cow dung substrate (4813 ± 62 U g−1). Physiological fermentation factors such as the incubation time (72 h), the pH (9), the moisture content (120%), and the inoculum level (6%) played a vital role in the enzyme bioprocess. The enzyme production improved with the supplementation of maltose and yeast extract as carbon and nitrogen sources, respectively. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis and zymogram analysis of the purified protease indicated an estimated molecular mass of 46 kDa. The protease enzyme was stable over a temperature range of 40–50 °C and pH 6–9, with maximum activity at 50 °C and pH 8. Among the divalent ions tested, Ca2+, Na+ and Mg2+ showed activities of 107 ± 0.7%, 103.5 ± 1.3%, and 104.6 ± 0.9, respectively. The enzyme showed stability in the presence of surfactants such as sodium dodecyl sulfate and on various commercially available detergents. The crude enzyme effectively de-haired goat hides within 18 h of incubation at 30 °C. The enzymatic properties of this protease suggest its suitable application as an additive in detergent formulation and also in leather processing. Based on the laboratory results, the use of cow dung for producing and extracting enzyme is not cumbersome and is easy to scale up. Considering its cheap cost and availability, cow dung is an ideal substrate for enzyme bioprocess in an industrial point of view.
    Saudi Journal of Biological Sciences 01/2014; 21(1):27–34. · 0.74 Impact Factor